Metatarsophalangeal joint of the great toe: normal MR,MR arthrographic,and MR bursographic findings in cadavers

OBJECTIVE: To demonstrate the normal anatomy of the metatarsophalangeal (MTP) joint of the great toe with MR imaging, MR arthrography, and MR bursography. MATERIALS AND METHODS: MR images of 12 cadaveric MTP joints of the great toe were obtained before and after arthrography, busography, or both. The MR appearances of all articular and periarticular structures were analyzed and correlated with those seen on anatomic sections. RESULTS: The sesamoid bones and ligaments, the deep transverse metatarsal ligament, and the tendon attachments of the abductor and adductor hallucis muscles were seen best in the coronal plane. The sagittal plane was best for evaluating the plantar plate, the articular cartilage, and the tendon attachments of the flexor and extensor hallucis brevis muscles. The main collateral ligaments were evaluated best in the axial plane. MR arthrography improved the visualization of all articular and periarticular structures except the collateral ligament complexes. MR bursography did not enhance the visualization of these structures. CONCLUSIONS: MR imaging and MR arthrography allow accurate visualization of the important anatomic structures in and about the MTP joint of the great toe.     

MR imaging of the metacarpophalangeal joints of the fingers: part I. Conventional MR imaging and MR arthrographic findings in cadavers

PURPOSE: To demonstrate the normal anatomy of the metacarpophalangeal (MCP) joints of the fingers with magnetic resonance (MR) imaging and MR arthrography in cadavers. MATERIALS AND METHODS: MR images of 20 MCP joints of the fingers of five fresh human cadaveric hands in the extended and flexed positions were obtained before and after arthrography. The MR appearances of all articular and periarticular structures were analyzed and compared with those seen on anatomic sections. Two readers independently graded the visibility of these structures. Interobserver agreement was tested by using the kappa statistic. RESULTS: The main collateral ligaments could be best evaluated on the transverse images of flexed fingers. The accessory bands of the collateral ligament complex were best seen on the transverse images of extended fingers. Sagittal MR images were best for evaluating the palmar plate and the capsule. MR arthrography improved the visualization of all articular and periarticular structures. The kappa values related to conventional MR imaging findings at all sequences, 0.42-0.71, indicated moderate to substantial agreement. The kappa values for the MR arthrographic sequences, 0.59-0.74, were slightly higher than those for the nonenhanced sequences. CONCLUSION: Conventional MR imaging and MR arthrography enable accurate visualization of the important anatomic structures of the MCP joints. MR arthrography enhances visualization of the intraarticular elements.     

Pisotriquetral joint: assessment with MR imaging and MR arthrography

PURPOSE: To evaluate magnetic resonance (MR) imaging and MR arthrographic findings in the pisotriquetral joint (PTJ) and their contribution to assessment of PTJ osteoarthritis. MATERIALS AND METHODS: Images of 22 fresh human cadaveric PTJs were obtained with both conventional and arthrographic MR techniques. The MR appearances of all intraarticular and periarticular structures were analyzed and correlated with anatomic slices. Two readers graded visibility of anatomic structures and severity of joint abnormalities. Differences in the visibility ratings at standard MR imaging and at MR arthrography were calculated. Association between the type of pisiform insertion of ligament or muscle with cartilaginous abnormalities of the PTJ was assessed. The association between cartilaginous lesions and osteoarthritic changes was calculated. RESULTS: The tendon sheath, the fibrous capsule, and cartilaginous surfaces were better visualized at MR arthrography than at MR imaging. Pisohamate and pisometacarpal ligaments were slightly better seen on MR arthrograms. Tendons, muscles, and retinacular structures were well demonstrated at both conventional MR and MR arthrography. Cartilaginous lesions and osteophytes were easily identified and were detected more often in the pisiform bone than in the triquetral bone. Communication of the PTJ with the radiocarpal joint was noted in 18 (82%) of 22 wrists. CONCLUSION: MR imaging and/or MR arthrography allows visualization of all anatomic structures of the PTJ. MR arthrography improves visualization of findings of osteoarthritis.     

Ligamentous and tendinous anatomy of the intermetacarpal and common carpometacarpal joints: evaluation with MR imaging and MR arthrography.

PURPOSE: The purpose of this work was to demonstrate the normal ligamentous and tendinous anatomy of the intermetacarpal (IMC) and common carpometacarpal (CCMC) joints with MRI and MR arthrography. METHOD: MR images of 22 wrists derived from fresh human cadavers were obtained before and after arthrography. The MR imaging features of the ligaments and tendons about the CCMC and IMC joints and the joints themselves were analyzed in a randomized fashion and correlated with those seen on anatomic sections. RESULTS: Six CCMC ligaments were visualized. The dorsal and palmar CCMC ligaments and the pisometacarpal ligament were best visualized in the sagittal plane. The radial and ulnar CCMC collateral ligaments and the capito-third metacarpal ligament were best visualized in the coronal plane. Three main IMC ligaments were observed: a dorsal and a palmar ligament and an interosseous ligament complex. All three ligaments were best visualized in the axial plane. Four tendinous insertions to the metacarpal bases were evident. CONCLUSION: The anatomy of the ligaments and tendinous insertions about the second to fifth IMC and the CCMC joints is well demonstrated by MR imaging and MR arthrography. MR arthrography does not significantly improve the visualization of these complex structures.     

Extrinsic carpal ligaments: normal MR arthrographic appearance in cadavers

PURPOSE: To describe the normal magnetic resonance (MR) arthrographic anatomy of the major carpal ligaments (excluding scapholunate and lunotriquetral ligaments) and their osseous attachments by using standard imaging planes. MATERIALS AND METHODS: MR images of 22 wrists derived from fresh human cadaveric hands were obtained after tricompartmental arthrography. The MR arthrographic appearance of the carpal ligaments and their bone attachments were analyzed and correlated to those seen on anatomic sections. Two readers determined in consensus which was the best plane to observe the course and attachment sites for each ligament. They further analyzed the size and sites of attachment of these ligaments in two orthogonal planes chosen for optimal viewing. RESULTS: Each ligament was well seen as a hypointense linear structure with MR arthrography. The radioscaphocapitate, radiolunotriquetral, radioscapholunate, dorsal radiotriquetral, palmar scaphotriquetral, and dorsal scaphotriquetral ligaments were best evaluated in the transverse plane. The palmar and dorsal ulnotriquetral and ulnolunate ligaments were best visualized in the sagittal plane. The radial collateral ligament was best analyzed in the coronal plane. The attachment sites of all ligaments were best analyzed either in the transverse or sagittal planes. CONCLUSION: MR arthrography allows visualization of the carpal ligaments. Detailed knowledge of the normal appearance of these ligaments can serve as a baseline for future studies in which MR arthrography is used to characterize wrist instability.     

MR imaging of the metacarpophalangeal joints of the fingers: part II. Detection of simulated injuries in cadavers

PURPOSE: To evaluate and compare conventional magnetic resonance (MR) imaging and MR arthrography in the diagnosis of the most common traumatic metacarpophalangeal (MCP) joint injuries, which were created surgically in cadavers. MATERIALS AND METHODS: Injuries to various MCP joint structures were surgically created randomly in 28 fingers of seven human cadaveric hands. Injuries to the main collateral ligaments (CLs) (n = 12), accessory CL (n = 15), sagittal band (n = 14), transverse fibers of the extensor hood (n = 5), first annular pulley (n = 16), deep transverse metacarpal ligament (DTML) (n = 5), and palmar plate (n = 10) were analyzed. Conventional MR images and MR arthrograms were evaluated, with differences in interpretation resolved in consensus. The sensitivities, specificities, and accuracies of both MR imaging methods were determined, and the differences were tested for significance by using the McNemar test. RESULTS: Sensitivity was 28.6%-93.8% with conventional MR imaging versus 50.0%-93.3% with MR arthrography. Specificity was 66.7%-100% with conventional MR imaging versus 83.3%-100% with MR arthrography. Although the MR arthrographic results usually were higher, the differences were not significant. The kappa values for interobserver agreement were 0.314-0.638 for conventional MR imaging versus 0.364-1.00 for MR arthrography. Sensitivity for the detection of lesions of the main and accessory CLs and the first annular pulley was slightly higher than that for the detection of lesions of the extensor hood, DTML, and palmar plate structures. CONCLUSION: MR imaging and MR arthrography enable the diagnosis of simulated MCP joint injuries. MR arthrography does not have a significant advantage over conventional MR imaging.     

Rotator cuff interval: evaluation with MR imaging and MR arthrography of the shoulder in 32 cadavers

PURPOSE: The purpose of this work was to establish the optimal means of evaluation of the rotator cuff interval (RCI) and rotator interval capsule and demonstrate normal anatomy of the RCI using MR imaging and MR arthrography. METHOD: MR arthrography was performed in 32 cadaveric shoulders. In 20 cases, MR imaging was completed prior to arthrography. Pre- and postarthrography studies included standard imaging planes. Images were evaluated by the consensus of two musculoskeletal radiologists with attention to the RCI, rotator interval capsule (measurements on postarthrographic studies), and crossing structures. In five cases, specialized imaging planes were performed after arthrography. RESULTS: The RCI, rotator interval capsule, and crossing structures were best evaluated by MR arthrography. The anteroposterior dimension of the rotator interval capsule could be best depicted on postarthrogram images. CONCLUSION: MR arthrography, with both standard and specialized imaging planes, is a useful way to evaluate the RCI, the rotator interval capsule, and its crossing structures.     

Anterior bundle of ulnar collateral ligament: evaluation of anatomic relationships by using MR imaging, MR arthrography, and gross anatomic and histologic analysis

PURPOSE: To evaluate the gross and microscopic anatomy and the magnetic resonance (MR) imaging and MR arthrographic appearance of the anterior bundle of the ulnar collateral ligament (UCL) of the elbow. MATERIALS AND METHODS: The origin and insertion of the anterior bundle of the UCL, the bundle's relationship to the overlying flexor tendons, and the presence of a layered configuration were assessed through inspection and dissection of an elbow specimen. T1-weighted spin-echo MR imaging and MR arthrography in standard imaging planes and a coronal oblique plane were performed in eight other elbow specimens. Additional MR arthrography was performed in four specimens by using the coronal plane with the elbow in 20 degrees of flexion. The specimens were then cut in planes corresponding to those of the MR images. Histologic analysis of two specimens was performed. RESULTS: The anterior bundle of the UCL appeared as a low-signal-intensity structure on T1-weighted spin-echo MR and MR arthrographic images. It consisted of a uniform layer of parallel collagen fibers attaching proximally to the base of the medial epicondyle of the humerus and distally to the medial aspect of the coronoid process of the ulna (sublime tubercle). A layer of synovium separated the anterior bundle from the more superficial tendon of the flexor digitorum superficialis muscle. MR imaging-anatomic comparison in four (50%) specimens revealed separation between the anterior bundle of the UCL and the sublime tubercle. Results of histologic analysis of two of these specimens confirmed insertion of the anterior bundle of the UCL 3 and 4 mm distal to the articular margin. Ligamentous degeneration was detected in only one of these specimens. CONCLUSION: There is variability in the distal insertion of the anterior bundle, and this suggests that caution should be exercised in the diagnosis of its partial detachment from the sublime tubercle of the ulna.     

Superior labral anteroposterior lesions: MR arthrography with arm traction.

OBJECTIVE: The purpose of this study was to investigate the efficacy of arm traction combined with MR arthrography in the evaluation of superior labral anteroposterior (SLAP) lesions. MATERIALS AND METHODS: Cadaveric shoulders were studied with a 1.5-T MR imaging unit with the arm externally rotated. Fifteen milliliters of a gadolinium-containing contrast agent were injected into the glenohumeral joint. Twenty-four sets of images of cadaveric joints were evaluated independently by two observers. These sets consisted of MR arthrographic images obtained with traction (applied to the wrist using 1- to 3-kg weights) and without traction in five shoulders in which SLAP lesions had been excluded arthroscopically or by cadaveric sectioning; and MR arthrographic images obtained with and without traction in seven shoulders in which various types of SLAP lesions had been created arthroscopically and later confirmed by cadaveric sectioning. RESULTS: Analysis of the data indicated that MR arthrography in combination with arm traction and external rotation improved diagnostic accuracy with regard to identification and categorization of SLAP lesions when compared with studies made without traction. CONCLUSION: The combination of MR arthrography and arm traction with the shoulder in external rotation provides a more effective approach for detection of SLAP lesions than does similar MR arthrography performed without arm traction.     

MR imaging,MR arthrography,and specimen correlation of the posterolateral corner of the knee: an anatomic study

OBJECTIVE: We sought to evaluate the anatomy of the posterolateral aspect of the knee with anatomic dissection, MR imaging, MR arthrography, and sectional anatomy. MATERIALS AND METHODS: We assessed the posterolateral corner of the knee during dissection of one gross anatomic specimen. MR imaging and MR arthrography were performed in seven additional knee specimens. T1-weighted spin-echo MR images were obtained in the standard imaging planes as well as in the coronal oblique plane. The specimens underwent T1-weighted spin-echo MR imaging after administration of intraarticular contrast material and were sectioned into planes corresponding to those of the MR images. RESULTS: At anatomic dissection, the following posterolateral structures were identified: the arcuate ligament (medial and lateral limbs), fabellofibular ligament, popliteofibular ligament, popliteus tendon and its two posterior attachments to the lateral meniscus, fibular collateral ligament, direct and anterior arms of the tendon of the long head of the biceps femoris muscle, and direct and anterior arms of the tendon of the short head of the biceps femoris muscle. Correlation of MR imaging and anatomic findings showed that the popliteofibular ligament and oblique popliteal ligament were found in 57% and 100% of specimens, respectively. At least one of the two limbs of the arcuate ligament was identified in 71% of specimens. The fabellofibular ligament was not identified on MR images in any of the specimens. The anteroinferior and posterosuperior popliteomeniscal fascicles were identified in all specimens. CONCLUSION: The posterolateral corner of the knee comprises complex and variable anatomic structures. Recognition of these variations is important in the assessment of MR images of the knee.     

MR Arthrography of the Hip

Magnetic resonance imaging (MRI) of the hip has been valuable in the diagnosis of occult osseous abnormalities and of periarticular soft tissue disorders. MRI has been less useful in the evaluation of acetabular labral tears and other intra-articular abnormalities. Image optimization is more technically challenging in the hip than in smaller joints because the overlying soft tissues are thicker, resulting in decreased spatial and contrast resolutions that may not be adequate to distinguish the acetabular labrum from subchondral bone, articular cartilage, and joint capsule. MR arthrography (MRA) extends the capabilities of conventional MRI because contrast solution separates intra-articular structures and outlines abnormalities. In hips with suspected acetabular labral injury, arthrographic MR images demonstrate the location and length of tears and the presence of associated capsular defects. Arthrographic MR images may also enable the accurate diagnosis of cartilage lesions and intra-articular loose bodies. This article illustrates normal arthrographic MR features of the hip as well as pathologic disorders of the acetabular labrum, capsule, and articular cartilage     

Special focus session. MR arthrography.

Direct magnetic resonance (MR) arthrography with injection of saline solution or diluted gadolinium can be useful for evaluating certain pathologic conditions in the joints. It is most helpful for outlining labral-ligamentous abnormalities in the shoulder and distinguishing partial-thickness from full-thickness tears in the rotator cuff, demonstrating labral tears in the hip, showing partial- and full-thickness tears of the collateral ligament of the elbow and delineating bands in the elbow, identifying residual or recurrent tears in the knee following meniscectomy, increasing the certainty of perforations of the ligaments and triangular fibrocartilage in the wrist, correctly identifying ligament tears in the ankle and increasing the sensitivity for ankle impingement syndromes, assessing the stability of osteochondral lesions in the articular surface of joints, and delineating loose bodies in joints. Indirect MR arthrography with intravenous administration of diluted gadolinium may be performed when direct arthrography is inconvenient or not logistically feasible. Although indirect MR arthrography has some disadvantages vis-à-vis direct MR arthrography, it does not require fluoroscopic guidance or joint injection and it is superior to conventional MR imaging in delineating structures when there is minimal joint fluid. In addition, vascularized or inflamed tissue will enhance with this method. Indirect MR arthrography can be used to rule in or diagnose abnormalities and to exclude abnormalities.     

Gamekeeper thumb: Diagnosis of ulnar collateral ligament injury using magnetic resonance imaging,magnetic resonance arthrography and stress radiography

Ulnar collateral ligament (UCL) tears may be nondisplaced or displaced relative to the adductor pollicis aponeurosis. Nondisplaced tears typically heal with immobilization whereas displaced tears require surgery. Nineteen patients with UCL injuries were evaluated using MR imaging (MRI), MR arthrography, and stress radiography (SR) to determine the efficacy of these techniques in differentiating nondisplaced from displaced UCL tears. Nineteen patients with UCL injuries were evaluated. MRI was utilized in 5 patients, and MR arthrography in 14, with 12 of these 14 undergoing SR. They were followed until resolution of symptoms; those without relief, and those with suspected displaced UCL tears were surgically explored. Surgery and imaging was correlated. Eight patients underwent surgical repair. SR was abnormal in six patients treated surgically, but was negative in four of six conservatively treated patients with MR findings of nondisplaced tears. All patients with MR or MR arthrographic findings interpreted as being normal or as having a nondisplaced tear improved after conservative treatment. Based on surgical findings and clinical follow-up, MR arthrography accurately diagnosed 13 of 14 UCL injuries, with one false-positive interpretation. SR is often falsely negative. MR imaging with or without intra-articular contrast injection proved to be accurate in a small series of patients with UCL injuries.     

MR and CT arthrography of the elbow

Magnetic resonance (MR) arthrography has, to a great extent, replaced conventional and CT arthrography as the standard of care imaging tool for indications including medial elbow pain in the throwing athlete, chondral and osteochondral lesions in the elbow, and intra-articular bodies. There are still rare specific incidences where CT arthrography is indicated. This article reviews elbow arthrography, with a greater emphasis placed on MR arthrography, including indications, technique, potential complications, contraindications, equipment, and MR arthrographic pathologies.     

MR imaging of the metacarpophalangeal joints of the fingers: evaluation of 38 patients with chronic joint disability

Objective To report the MR imaging findings of painful injured metacarpophalangeal (MCP) joints of the fingers.Design and patients MR imaging of 39 injured MCP joints in 38 patients was performed after a mean delay of 8.8 months. The MR images were obtained with the fingers in extended and flexed positions using T2-weighted and T1-weighted sequences before and after intravenous injection of a gadolinium compound. Ten patients were treated surgically. Mean clinical follow-up was 1.8 years.Results Tears of the collateral ligaments were the most common lesion (30/39), most being radial in location. Contrast-enhanced axial T1-weighted images with the MCP joint in a flexed position showed these lesions optimally. Ten tears were partial and 20 were complete. In 13 patients, MR images showed 17 associated lesions including injuries of the extensor hood (10/17), interosseous tendon (3/17), palmar plate (3/17), and an osteochondral lesion (1/17). Sagittal MR images were essential to highlight palmar plate tears.Conclusion Partial or complete tears of the collateral ligaments are prevalent MR imaging findings in patients with chronic disability resulting from injuries to the MCP joints. Although conservative treatment generally is sufficient for isolated injuries of the collateral ligaments, surgical repair is often required in cases of more extensive injuries. MR imaging may clearly delineate associated lesions of and about the MCP joints.     

MR arthrography of shoulders after suture-anchor Bankart repair

PURPOSE: To determine the ability of magnetic resonance (MR) arthrography to depict the anatomic reestablishment of the capsulolabral complex after suture-anchor Bankart repair. MATERIALS AND METHODS: Thirty patients (25 men, five women; mean age, 28 years) who had undergone suture-anchor Bankart repair of one shoulder underwent MR arthrography before second-look arthroscopy. Ninety-eight anchors were used for the sutures. MR arthrographic diagnosis of anatomic reestablishment of the capsulolabral complex was correlated with arthroscopic findings. Contingency table analysis was performed to determine the relationship between MR arthrographic findings and arthroscopic findings. RESULTS: MR findings of reattachment of the capsulolabral complex were in agreement with arthroscopic findings in 93 anchor points (accuracy, 93 of 98 anchor points; 95%). In 28 shoulders, oblique transverse images obtained with the shoulder in the abduction and external rotation position showed that the anterior band of the inferior glenohumeral ligament (AIGHL) abutted the humeral head and that reattachment of the AIGHL to the glenoid rim was seamless. Arthroscopy revealed satisfactory reestablishment of the capsulolabral complex in these shoulders. In the remaining two shoulders, a pool of contrast material was seen between the AIGHL and humeral head and a "divot" was detected at the point of reattachment of the AIGHL to the glenoid rim. Arthroscopy revealed unsatisfactory reestablishment of the capsulolabral complex. MR arthrographic findings of reattachment of the AIGHL were significantly associated with arthroscopic findings of reestablishment of the capsulolabral complex (P <.01). CONCLUSION: MR arthrography can be reliably used for the postoperative assessment of suture-anchor Bankart repair.     

Posterior cruciate ligament recess and normal posterior capsular insertional anatomy: MR imaging of cadaveric knees

PURPOSE: To analyze the normal pattern of fluid accumulation adjacent to the posterior cruciate ligament and anatomic variations of joint capsule insertion sites in the posterosuperior corner of the human knee by using magnetic resonance (MR) imaging in cadaveric specimens. MATERIALS AND METHODS: Fourteen fresh cadaveric knees (obtained and used according to institutional guidelines, with informed consent from relatives of the deceased) from 11 men and three women (six left knees, eight right knees; age range, 70-82 years at time of death; mean age, 76 years +/- 4.4 [standard deviation]) were studied with high-spatial-resolution MR imaging performed before and after intraarticular injection of 35-45 mL gadopentetate dimeglumine. MR images were evaluated by two readers in consensus, with emphasis on location of fluid posterior to the posterior cruciate ligament, communication of that fluid with the medial or lateral compartment of the knee, and the relation of fluid to surrounding structures. Readers also were asked to measure, in the sagittal plane, the distance between the posterior capsular insertion sites and the femoral physeal scar. For anatomic analysis, cadaveric specimens were sectioned in 3-mm-thick slices in the sagittal plane that approximated the sections acquired at MR imaging. RESULTS: In all 14 cadaveric specimens, MR arthrographic images showed a fluid collection behind the posterior cruciate ligament (in the posterior cruciate ligament recess), a finding not evident on images obtained prior to contrast material injection. The recess was distended during flexion, and it communicated only with the medial femorotibial compartment in all cases. Posterior to the posterior cruciate ligament recess, a fat pad was observed in all specimens. Incomplete joint capsule was seen behind the fat pad in seven specimens. Joint capsule insertion was at the level of the femoral physeal scar or between it and a point 15 mm above it. CONCLUSION: The posterior cruciate ligament recess has specific characteristics that allow its identification: communication with the medial compartment of the knee and absence of the adjacent joint capsule.     

Sonography of the scapholunate ligament in four cadaveric wrists: correlation with MR arthrography and anatomy

OBJECTIVE: The objective of our study was to sonographically characterize the dorsal aspect of the scapholunate ligament in cadaveric wrists using arthrography, MR arthrography, and anatomic correlation as the gold standard. MATERIALS AND METHODS: The dorsal aspect of the scapholunate ligament in four cadaveric wrists was evaluated on sonography without knowledge of the findings from standard arthrography, MR arthrography, and anatomic sectioning. The sonographic findings were compared with the findings from other modalities. The criteria for an abnormal scapholunate ligament included an abnormal contrast communication between the radiocarpal and midcarpal joints on arthrography and a discontinuity of the dorsal aspect of the scapholunate ligament that was documented both on MR arthrography and at anatomic sectioning. RESULTS: Arthrography, MR arthrography, and anatomic sectioning showed the dorsal aspect of the scapholunate ligament to be normal in one specimen and abnormal in three specimens. On sonography, the normal scapholunate ligament was hyperechoic between the scaphoid and lunate bones. In the three cases of abnormality, a normal scapholunate ligament was not visualized, and an abnormal hypoechogenicity was present. CONCLUSION: The dorsal aspect of the scapholunate ligament can be depicted on sonography; abnormality is present in patients in whom the normally hyperechoic fibrillar ligament is hypoechoic or absent.     

Arcuate ligament of the wrist: normal MR appearance and its relationship to palmar midcarpal instability: a cadaveric study

Objective To describe the magnetic resonance (MR) imaging and gross anatomic appearance of the scaphocapitate (SC) ligament and triquetrohamocapitate (THC) ligament, which are the radial and ulnar limbs of the composite arcuate ligament, a critical volar midcarpal stabilizing ligament. Design T1 spin-echo and 3D gradient-echo MR imaging in the standard, coronal oblique, and axial oblique planes were performed both before and following midcarpal arthrography in seven cadaveric wrists. The seven specimens were then sectioned in selected planes to optimally visualize the SC and THC ligaments. These specimens were analyzed and correlated with their corresponding MR images. Results The SC and THC ligaments can be visualized in MR images as structures of low signal intensity that form an inverted “V” joining the proximal and distal carpal rows. The entire ligamentous complex is best visualized with coronal and axial oblique MR imaging but can also be seen in standard imaging planes. Conclusion SC and THC ligaments together form the arcuate ligament of the wrist. Their function is crucial to the normal functioning of the wrist. Palmar midcarpal instability (PMCI) is a resulting condition when abnormalities of these ligaments occur. Dedicated MR imaging in the coronal and axial imaging planes can be performed in patients suspected of having PCMI.     

Collateral ligaments of the ankle: high-resolution MR imaging with a local gradient coil and anatomic correlation in cadavers.

Findings at high-resolution magnetic resonance (MR) imaging of the lateral and medial collateral ligaments of the ankle were compared with findings in anatomic sections from cadavers. MR imaging of six cadaveric feet was performed with a newly developed local gradient coil and axial and coronal T1-weighted spin-echo sequences. Axial imaging provided optimum views of the anterior and posterior talofibular ligaments, the deep layers of the medial collateral ligament, and the tibionavicular ligament. Coronal imaging allowed complete visualization of the calcaneofibular, posterior talofibular, tibiocalcaneal, and posterior tibiotalar ligaments. In both imaging planes, differentiation of the deep and superficial layers of the medial collateral ligament was possible. Differentiation between the syndesmotic complex and the lateral collateral ligament was accomplished easily; in particular, differentiation of the posterior tibiofibular ligament from the posterior talofibular ligament was not difficult because of the differing insertions of these ligaments. The inhomogeneous appearance of the medial collateral ligament and the posterior talofibular ligament on MR images correlated with areas of fatty tissue on corresponding microscopic sections. High-resolution MR imaging with a newly developed local gradient coil allows excellent visualization of the lateral and medial collateral ligaments of the ankle.